It is known that the reaction for producing glycidol from glycerol carbonate is desirably carried out in the presence of a neutral salt such as sodium sulfate, although the reaction proceeds by thermal decarboxylation of glycerol carbonate even without using any catalyst (for example, refer to Patent Documents 1 and 2).
On the other hand, it is also known that glycerol carbonate is produced by not only a method using phosgene but also a method of subjecting dimethyl carbonate, ethylene carbonate, propylene carbonate or the like and glycerol to exchange reaction therebetween, a method of obtaining the glycerol carbonate from glycerol and urea, etc. Among these methods, the method using glycerol and urea allows the glycerol carbonate to be produced in a facilitated manner at low costs. In this method, although the reaction proceeds even under a catalyst-free condition, it is known that the glycerol carbonate is produced with a high yield when using a Lewis acid such as zinc sulfate and magnesium sulfate as a catalyst in the reaction (for example, refer to Patent Document 3).
Patent Document 1: U.S. Pat. No. 2,856,413
Patent Document 2: JP 6-157509A
Patent Document 3: EP 0955298A